scholarly journals The efficacy of Hibiscus sabdariffa as a fibre-reinforcement material for denture base acrylic resins

2017 ◽  
Author(s):  
◽  
Kenneth Nkemdilim Okeke
Keyword(s):  
Fibre Diameter ◽  
Fibre Reinforcement ◽  
Hibiscus Sabdariffa ◽  
Main Study ◽  
Denture Base ◽  
Fibre Density ◽  
Acrylic Resins ◽  
Diameter Fibre ◽  
Reinforcement Material ◽  
Preliminary Study

The poor mechanical properties of denture base acrylic resins can cause dentures to fracture either through impact or stress fatigue. Various metal reinforcing materials such as powders, nets, plates and wires together with synthetic fibres are therefore used to improve the strength properties of denture base acrylic resins. Despite their benefits, they are difficult to apply during fabrication, are costly, non-recyclable, and not environmentally friendly. The suitability of Hibiscus sabdariffa (H. sabdariffa) as a fibre reinforcement material for denture base acrylic resins was therefore investigated. A quantitative research paradigm and a two-phased experimental research design was used. The preliminary study used Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA) and field emission scanning electron microscope (FE-SEM) to assess the characteristics of, and the effect of, mercerisation on H. sabdariffa fibres. In determining the suitability of H. sabdariffa fibres, fibre diameter, fibre density, moisture content and absorption were examined. The main study investigated the mechanical and physical properties of two sample groups namely: the unreinforced (control) group and the H. sabdariffa fibre-reinforced (test) group denture base acrylic resins. The flexural strength, impact strength, specific wear rate, hardness and water absorption behaviour were determined in line with ASTM D 790 and D 256, G 99, D 2583 and D 570 methods of testing, respectively. Parametric and non-parametric tests were used to analyse the mean differences (p = 0.05) between the unreinforced and the H. sabdariffa fibre-reinforced denture base acrylic resins. The preliminary study revealed that H. sabdariffa fibres favourably compared to other lignocellulosic fibres in terms of fibre diameter, fibre density, water content and absorption behaviour. In the main study, a t-test revealed that there were significant differences in flexural strength at 0oC (p < 0.0001) and at 65oC (p < 0.0025) between the two sample groups. Similarly, there were significant differences in the impact strength between the two sample groups at 0oC (p < 0.031) and at 65oC (p < 0.0001). In contrast to the 200g load, there were significant differences (p < 0.044) in the specific wear rate of the unreinforced and the H. sabdariffa fibre-reinforced denture base acrylic resins at the 500g load. The hardness values revealed no significant differences (p > 0.707) between the two sample groups. There were however, significant differences (p < 0.041) in the water absorption rate between the two sample groups. Overall, the prominent features of this study showed that H. sabdariffa fibre is a suitable reinforcement fibre material for denture base acrylic resins and is in compliance with ISO 1567: 1999. Although this study found that H. sabdariffa fibres can be used as reinforcement material for denture base acrylic resins, the results cannot be generalised to clinical conditions, therefore in vitro and in vivo investigations are recommended.

scholarly journals Selection of Eucalyptus camaldulensis Families for Sustainable Pulpwood Production by Means of Anatomical Characteristics

Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 31
Author(s):  
Ikumi Nezu ◽  
Futoshi Ishiguri ◽  
Haruna Aiso ◽  
Sapit Diloksumpun ◽  
Jyunichi Ohshima ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Fibre Diameter ◽  
Eucalyptus Camaldulensis ◽  
Principal Component ◽  
Wood Properties ◽  
Component Analysis ◽  
Pulp And Paper ◽  
Anatomical Characteristics ◽  
Diameter Fibre ◽  
Sib Families

Sustainable pulpwood production from fast-growing tree plantations is needed for pulp and paper industries. To increase the pulpwood production efficiency, the anatomical characteristics and derived-wood properties of 75 trees from 15 half-sib families of Eucalyptus camaldulensis Dehnh. planted in Thailand were investigated, and then the family was classified by suitability of wood as raw material for pulp and paper products using principal component analysis and clustering. The mean values of vessel diameter, vessel frequency, fibre diameter, fibre lumen diameter, and fibre wall thickness at 2 cm from the cambium were 128 µm, 16 no./mm2, 11.1 µm, 7.1 µm, and 1.88 µm, respectively. In addition, the Runkel ratio, Luce’s shape factor, flexibility coefficient, slenderness ratio, solids factor, and wall coverage ratio (i.e., derived-wood properties) were 0.53, 0.42, 0.64, 85.3, 68 × 103 µm3, and 0.34, respectively. Significant differences in fibre diameter, fibre lumen diameter, and Runkel ratio were found among families. Although significant differences among families were not found for other anatomical characteristics and derived-wood properties, the p-values obtained by an analysis of variance test ranged from 0.050 to 0.088. Based on the results of a principal component analysis and cluster analysis, 15 families were classified into four clusters with different expected pulp and paper characteristics. The suitability of wood from E. camaldulensis half-sib families for pulp and paper can be evaluated by principal component analysis using anatomical characteristics and physical properties as variables. Based on the results, desirable pulp and paper quality may be obtained through the selection of families from this species.

Does microwave disinfection affect the dimensional stability of denture base acrylic resins? A systematic review

Gerodontology ◽  
2021 ◽  
Author(s):  
Rodrigo Moreira Bringel Costa ◽  
Helena Sandrini Venante ◽  
Mariana Domingues Pordeus ◽  
Ana Paula Chappuis‐Chocano ◽  
Karin Hermana Neppelenbroek ◽  
...  
Keyword(s):  
Systematic Review ◽  
Dimensional Stability ◽  
Denture Base ◽  
Acrylic Resins

scholarly journals Porosity, water sorption and solubility of denture base acrylic resins polymerized conventionally or in microwave

2018 ◽  
Vol 26 (0) ◽  
Author(s):  
Rosana Marques Silva Figuerôa ◽  
Bruna Conterno ◽  
César Augusto Galvão Arrais ◽  
Carolina Yoshi Campos Sugio ◽  
Vanessa Migliorini Urban ◽  
...  
Keyword(s):  
Water Sorption ◽  
Denture Base ◽  
Acrylic Resins

scholarly journals Changes in The Number of Mold and Acceptance Rate of Kappaphycus alvarezii Jelly Candy Packed with Edible Film Gelatin-CMC During Storage

2022 ◽  
Vol 6 (6) ◽  
Author(s):  
Asri Silvana Naiu ◽  
Nikmawatisusanti Yusuf ◽  
Yusnina Hudongi
Keyword(s):  
Storage Time ◽  
Transmission Rate ◽  
Kappaphycus Alvarezii ◽  
Edible Film ◽  
Main Study ◽  
Main Research ◽  
Test Parameters ◽  
Preliminary Study ◽  
Two Stages ◽  
The Relationship

This study aimed to analyze changes in the number of molds and the level of panelist acceptance of K. alvarezii jelly candy packaged using gelatin-CMC edible film during storage. The method used in this study is a laboratory experimental method which consists of two stages, namely preliminary research which aims to determine the best edible film formula to be used as jelly candy packaging and the main research to analyze changes in the number of molds and the level of acceptance of appearance, taste, aroma and texture of jelly candy that has been packaged using a gelatin-CMC edible film during storage. Storage for 60 days was converted to 15 days in a climatic chamber with a temperature of 40 ℃ and a humidity of 75%. Sampling was carried out every 3 days. The research design used linear regression to see the relationship between storage time and test parameters. The results of the preliminary study showed the best formula for edible film, namely 1% gelatin, 0.3% bees wax, 0.75% CMC, and 0.3% glycerol which resulted in a water vapor transmission rate of 18.60 g/m2/24 hours. The results of the main study showed that storage time had a moderate effect on mold. Mold was detected on the last day of observation, storage time had a very strong effect on the level of acceptance which decreased with storage time. The organoleptic value of jelly candy packaged using gelatin-CMC edible film was still acceptable to the panelists until the 36th day of storage.

scholarly journals Effect of repeated cycles of chemical disinfection in microhardness of acrylic resins of complete denture base

2017 ◽  
Vol 65 (3) ◽  
pp. 196-201
Author(s):  
Elisa das Graças MARTINS ◽  
Rafael Tobias MORETTI NETO
Keyword(s):  
Sodium Hypochlorite ◽  
Knoop Hardness ◽  
Sodium Hypochlorite Solution ◽  
Chlorhexidine Digluconate ◽  
Water Control ◽  
Denture Base ◽  
Acrylic Resins ◽  
Hardness Tests ◽  
Before And After ◽  
Edentulous Patients

ABSTRACT Objective: To evaluate the microhardness of specimens of acrylic resins VipiCril® (thermally polymerized resin) and Bosworth New Truliner® (self-polymerized resin), before and after immersion in solutions of 0.12% chlorhexidine digluconate, 1% sodium hypochlorite, Corega Tabs® and water (control), testing the null hypothesis that the mouthwashes and chemicals used to disinfect complete dentures do not interfere with the superficial microhardness, and can therefore be used as adjuncts to oral hygiene of edentulous patients. Methods: Sixty specimens of resin VipiCril®(thermally polymerized resin) and 60 specimens of resin Bosworth New Truliner® (self-polymerized resin) measuring 16 mm of diameter and 6 mm of height were prepared, which were randomly divided into four groups of 15 specimens each, undergoing Knoop hardness tests (KHN) both before and after cycles of immersion in solutions of 0.12% chlorhexidine digluconate, 1% sodium hypochlorite, Corega Tabs® and water (control). Results: The specimens of resins VipiCril and Bosworth immersed in solutions of 0.12% chlorhexidine, Corega Tabs® and water showed decreased microhardness. Conclusion: The 1% sodium hypochlorite solution caused least damage to the denture structure, not leading to decrease of the superficial microhardness.

Effect of microwave irradiation and water storage on the viscoelastic properties of denture base and reline acrylic resins

2012 ◽  
Vol 5 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Carlos Eduardo Leão Lombardo ◽  
Sebastião Vicente Canevarolo ◽  
José Maurício dos Santos Nunes Reis ◽  
Ana Lucia Machado ◽  
Ana Claudia Pavarina ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Viscoelastic Properties ◽  
Water Storage ◽  
Denture Base ◽  
Acrylic Resins

Surface Roughness of Denture Base Acrylic Resins After Processing and After Polishing

2006 ◽  
Vol 15 (3) ◽  
pp. 180-186 ◽  
Author(s):  
Julie C. Berger ◽  
Carl F. Driscoll ◽  
Elaine Romberg ◽  
Qing Luo ◽  
Geoffrey Thompson
Keyword(s):  
Surface Roughness ◽  
Denture Base ◽  
Acrylic Resins

Effect of pre- and postpolymerization on flexural strength and elastic modulus of impregnated, fiber-reinforced denture base acrylic resins

2008 ◽  
Vol 100 (6) ◽  
pp. 449-457 ◽  
Author(s):  
Luiz E. Bertassoni ◽  
Grayson W. Marshall ◽  
Evelise Machado de Souza ◽  
Rodrigo Nunes Rached
Keyword(s):  
Elastic Modulus ◽  
Flexural Strength ◽  
Fiber Reinforced ◽  
Denture Base ◽  
Acrylic Resins
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